How to remove a USB device from a cmd Command Prompt

First, you need to use the devcon tool provided by Microsoft. The following is Microsoft's introduction (http://support.microsoft.com/kb/311272/zh-cn ):
The devcon Utility is a command line utility that can replace the Device Manager. With devcon, you can enable, disable, restart, update, delete, and query a single device or a group of devices. Devcon also provides ProgramDeveloper-related information that cannot be seen in the Device Manager.

Devcon can be used for Microsoft Windows 2000, Windows XP, and Windows Server 2003, but cannot be used for Windows 95, Windows 98, or Windows Millennium Edition
Remember the following command:

(1) devcon remove USB \ class_08 and remove the USB mobile storage device connected to the computer. After this operation, you can unplug the USB device.
(2) If you have not unplugged the USB device after using the third command, you can ask him to re-identify it. Remember the following command:
Devcon rescan, the computer will re-scan the hardware changes, so that the USB is re-identified.